Donald Trump has told Americans to be wary of stifling political disagreement, only days after a 20-year-old gunman attempted to assassinate the US presidential hopeful at a campaign rally.

In his first public speech since the attempt on his life, Mr Trump told the crowds at the Republican National Convention in Milwaukee that his campaign should focus on “the issues facing our country and how to make America successful, safe, free and great again.”

“In an age when our politics too often divide us, now is the time to remember that we are all fellow citizens,” he said.

“We must not criminalise, dissent or demonise political disagreement, which is what’s been happening in our country lately at a level that nobody has ever seen before.”

Republican presidential candidate Donald Trump speaks during the final night of the 2024 Republican National Convention (Carolyn Kaster/AP)

He began his speech by giving his account of the failed assassination in Butler, Pennsylvania, on Saturday.

“I will tell you exactly what happened, and you’ll never hear it from me a second time because it’s actually too painful to tell,” he said.

“If I had not moved my head at that very last instant at the assassin’s bullet would have perfectly hit its mark and I would not be here tonight. We would not be together.”

He then explained what was going through his mind moments after the shots rang out on Saturday, after he fell to the stage as a bullet struck his ear.

Mr Trump continued his account of the assassination attempt by saying: “I wanted to do something to let (the crowd) know I was OK. I raised my right arm, looked at the thousands and thousands of people that were breathlessly waiting and started shouting ‘Fight, fight, fight’.

“For the rest of my life, I will be grateful for the love shown by that giant audience of patriots that stood bravely on that fateful evening in Pennsylvania.”

The former president added that he had spoken to the family of Corey Comperatore who died in the shooting, calling him an “unbelievable person” with a firefighter’s jacket and helmet bearing his name on the stage.

“He lost his life selflessly acting as a human shield to protect them from flying bullets,” he said. “He went right over the top of them and was hit.”

He also praised David Dutch and James Copenhaver who were injured and called for a moment’s silence for Mr Comperatore.